Heating system



W. F. MILLER Feb. 13, 1930.

HEATING SYJS'IEM Original Filed July 10, 1935 illefi PATENT OFFICE21.3150 nss'rnm srsrau William F. Miller, Evansville, Ind., assignor toIndustrial Engineering Corporation, Evansville,

Ind., acorporation Original No. 2,077,250, dated April 13, 1987, SerialNo. 30.875, July 10, 1935.

Application for reissue August 4, 1937, Serial No. 157,430

4 Claims.

The present invention relates to heating systems and moreparticularly'to automatically controlled heating systems and aimsgenerally to improve existing systems of that type.

Heretofore, automatically controlled heating systems, particularly thosedesigned for dwellings and'the like, are controlled by a room thermostatoperative to operate the heating unit periodically when the temperaturein the room in which the thermostat is located drops to a certain point.Usually the thermostat is set to operatethe heatgag unit when the roomtemperature drops to It is well known that such operation of the heatingunit, especially in colder climates, results in strata of cold airthrough the house, particularly adjacent the floor. This is because thewater in the boiler and heating system, in the case of a hot watersystem, cools 01f as the rooms cool 01!, and when the room thermostatagain operates the heating unit, a considerable delay occurs before theboiler. temperature is raised sufficiently to-heat the rooms The roomthermostat is usually placed on the wall about five feet above thefloor, this being referred to as the breathing line.

According to my invention, I provide means for operating the heatingunit at regular intervals of time, and for regular, variable adjustabledurations of time to maintain the boiler temperature sufllciently highto avoid cold air stratification.

This means may and preferably does operate independently of the roomthermostat but is subject to the furnace limit control device or switchto prevent operation of the furnace when the temperature thereof reachesa predetermined degree. s

In order better to illustrate the invention, reference is had to theaccompanying drawing,

wherein Fig. 1 shows a satisfactory arrangement illustrated as appliedto a hot water heating system having an electrically controlled oil orgas burner;\ i

Fig. 2 isa front elevation of one suitable time controlled switch foruse in the system illustrated ln'Flg. 1; and

Fig. 3 is an edge view thereof.

According to the illustrated embodiment of the invention, the heatingsystem may include a suitable fumace ill, herein illustrated as, of thehot water type adapted to heat and circulate heated 'water to theradiators ll located in the rooms form of time controlled switchillustrated in Figs.

2 and 3 may comprise a rotatable cam l5 driven by a constant speedsynchronous electric motor 16 receiving electrical energy from theconventional power line II, the speed of the cam being reduced so thatitwill make one revolution every 15 or 30 minutes as desired. A pluralityof. relatively movable switch arms iii-l9 are mounted upon a panel ofthe time controlled switch II and have their free ends engaging the caml5, said arms carrying contacts 2il2| connected by wires 22-23'toterminals 2425 respectively.

The cam l5 may comprise two cam disks i5 and I5 one for each of theswitch arms' l8 and 1!- respectively, and these disks may be relativelyadjustable so as to variably regulate the duration of time the switcharms are closed during each revolution of the cam l5. As will beapparentfrom a consideration of Figs. 2 and 3, rotation of the cam disks l5 andi5 in the direction of the arrow will maintain the switch arms i8l9apart and the circuit broken except when the arm I! rides off of theshoulder of the cam l5 and until the arm I9 rides oil of the shoulder ofthe cam l5. This duration is controlled by the relative positions of thecam shoulders, see Fig. 2, and may be variably adjusted by adjusting thedisk It relatively to the disk 15. Thus, during each rotation ofthe'cams i5l 5 the switch arms may be in contact to close the circuitfor a period of from 1 to 7 minutes. as may be desired, depending uponthe adjusted position of the cams The switch arms l8l9. are connectedthrough wires 22-23 and terminals 24-25 to lines 26--2l to theelectrically operated heating unit I2, the line 28 leading through afurnace limit control switch 28 of the type that opens when the boilerreaches a predetermined temperature. Stated another way, the switch 28only permitsgperation of the heating unit when thefumace is below apredetermined point at which the limit switch is set. Such switches arewell known and are not illustrated in detail herein. Thus the timecontrol switch is connected to the heating unit i2 in series with thelimit control switch 28.

In operation the synchronous motor. It is directly connected to thepowerlines I! and operates continuously at a constant speed to rotate thecams lS-ll, revolution in every 15 or 30 minutes as desired, and iscontrolled by the gearing of the switch ll. During each revol lution theswitch arms are closed to close the circuit through the furnace limitcontrol switch 28 to the electrically controlled heating unit I! tooperate the heating unit for a time of suiilcient duration to maintainthe room temperature 10 sufiiciently high to avoid strata of cold air.This duration of periodic burner operation may be variably adjusted for1 to '1 minutes as desired,

by the simple relative adjustment of the cams throughout definitevariably adjustable predetermined durations, the frequency of periodicfurnace operation being at substantially 15 minute intervals, and theduration thereof being variably. adjusted from 1'-7 minutes tointermittently supply heat to the radiator synchronously with saidperiodic furnace operation so as to substantially increase the baseboardtemperature of the room without substantially increasing the temperatureat the breathing line.

2. In a heating system, in combination with an electrically operatedfurnace and a heat distributing device located in the room to be heatedand connected with said furnace, a single electric circuit forcontrolling the operation of said furnace, a furnace thermostat and aroom thermostat in series with the control circuit, a time controlledthe heating unit llto cutout the switch It during mild weather. Underthese conditions the heating unit will only be operated subject to thecontrol of the room thermostat.

V It will be observed that the room thermostat II is connected inparallel to the time switch I and hence the latter will operateindependently of the former. However, in extremely cold weather it maybe n to have the heating .80 unit operated continuously for longerperiods of is the case when the system is subjected to relatively long"oiT periods. 7 Actual usage of my improved system proves not 45 only aneconomy in fuel but an actual increase of the room temperature at thebaseboard line of approximately four degrees without increase of thetemperature at the breathing line.

This patent isa continuation in part of my 60 prior copending,application Serial No. 100,62

filed December 1, 1933.

It is to be clearly understood that the above description andaccompanying drawing describing my invention as applied to hot waterheating 5 systems is intended for illustrative purposes only. Obviouslythe invention is applicable to hot air, steam, vapor and other systemsand the heating unit may obviously be of any type adapted to burn coal,oil, gas or other fuel. Also the system may be of the three wire typeand obviously may be either a low voltage or high voltage system withoutdeparting from the spirit of the invention.

I claim: 1. In a heating system, in combination with an electricallyoperated furnace and a heat distribiiting radiator located in the roomto be heated and connected with said furnace, a single elec-- triccircuit for controlling the operation of said i furnaces furnacethermostat and a room thermostat in series with the control circuit, atime controlled switchconnected in parallel solely with switch connectedin parallel solely with the room thermostat for closing said furnacecircuit at frequent regular intervals of time and throughout it definitevariably adjustable predetermined durations independently of the roomtemperature, the frequency and duration of such periodic operation beingsuch as to intermittently supply heat to the radiator at such frequentintervals in synchronism with said predetermined furnace operation tomaintain heat therein so as to substantially increase the baseboardtemperature of the room without substantially increasing the temperatureat the breathing line. 3. In a heating system, in combination with anelectrically operated fluent fuel furnace and a heat distributingradiator located in the room to be heated and connected with saidfurnace, a single electric circuit for controlling the opera- 35 tion ofsaid furnace, a furnace thermostat and a room thermostat in series withthe control circuit, a time controlled switch connected in parallelsolely with the room thermostat for closing said furnace cireut atfrequent regular intervals of 0 time and throughout definite variablyadjustable predetermined durations, the frequency of furnace operationbeing in the order of one per 15 minutes and the duration thereof beingvariably adjusted from l to 7 minutes to intermittently (5 supply heatto the radiator in synchronisin with said periodic furnace operation soas to substantially increase the baseboard temperature of the roomwithout substantially increasing the temperature at the breathing line.5. 4. In a heating system, in combination with an electricallycontrolled furnace and a heat distributing device located in the room tobe heated and connected with said furnace, a furnace thermostat and aroom thermostat in series with the control 4 circuit: of a singleelectric circuit for controlling said furnace, a time controlled switchconnected in parallel solely to said room thermostat for operating saidfurnace at approximately fifteen minute intervals and throughoutdefinite variably 1 adjustable durations of time of substantially l to'1 minutes duration, said'time switch being operable to operate saidfurnace throughout said frequent, definite, variably adjusted durations,independently of the room temperature requirements to maintain asubstantial heat in said furnace and intermittently supply heat to saiddistributing device-synchronously with said periodic the room thermostatfor closing said furnace circuitlat frequent regular intervals 01' timeand furnace operation, and means for rendering said time controlledswitch inoperative during mild T0 weather in order that said furnace maybe controlled solely by roomand furnace thermostats.

WILLIAMF. MILLER.

